Modal Identification of Over-Damped Structural Systems Using Extended Ibrahim Time-Domain Method
In the previous study, the conventional Ibrahim time-domain method (ITD) using free-decay responses of structures has been extensively used in the modal-identification analysis, however, which is only applicable to identify the modal parameters of an under-damped structure. In the present paper, we propose a theoretical modification for ITD method, and extend the ITD method for modal identification of over-damped structural systems. The eigenvectors of the system matrix used in extended ITD method corresponding to the vibrating modes of a structural system in pair are sorted through the assurance index proposed in this paper based on the theory of structural dynamics. Numerical simulations confirm the validity of the proposed method for modal identification of over-damped structural systems.
KeywordsExtended Ibrahim time-domain modal-identification method Over-damped structural systems Identification of modal parameter
This research was supported in part of the financial funding provided by National Synchrotron Research Center (NSRRC). The first author would like to thank every member in the Optics Group of Experimental Facility Division, and Precision Mechanical Engineering Group of Instrumentation Development Division, NSRRC, for their kind assistance and friendship.
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